Ah yes, that failed, I remember. But would it still fail now that we have fold expressions? The 'unevaluated' aspects of op? are very verbose to emulate without additional language features.

On Wed, Jul 7, 2021 at 10:18 AM Ville Voutilainen <ville.voutilainen@gmail.com> wrote:
On Wed, 7 Jul 2021 at 12:02, Gašper Ažman via Std-Proposals
<std-proposals@lists.isocpp.org> wrote:
>
> How about proposing the elvis operator instead?

That would be http://open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4120.pdf,
which wasn't successful.
It's not at all obvious to me why something like this should have a
dedicated core language syntax,
as opposed to having a utility function along the lines of what's
suggested in this thread. The questions
about a language change motivation and its costs and concerns attached
to them don't really arise
for a utility function.